Fabrication of 0.62[0.75PMN-0.25PYbN]-0.38PT ceramics using one step calcination via combustion technique

The fabrication of 0.62[0.75Pb(Mg1/3Nb2/3)O 3-0.25Pb(Yb1/2Nb1/2)O3]-0. 38PbTiO3 ceramics (abbreviated PMN-PYbN-PT) by combustion technique using one step calcination was studied. Glycine was used as fuel to reduce the reaction temperature. The phase formation, microstructure, density and dielectric properties were investigated. It was shown that calcination method is more effective than conventional solid state reaction. The crystal structure of PMN-PYbN-PT ceramics exhibited a single rhombohedral perovskite phase in samples sintered at temperature T < 1200°C. The pyrochlore phase was found in the samples sintered at 1200°C. The average grain size of the ceramics increases with increasing sintering temperature. The density and the maximum dielectric constant increases with increasing sintering temperatures up to 1150°C, and then decreases at higher temperatures. The maximum density (8.04 g/cm³), highest dielectric constant (19000) and excellent ferroelectric properties (Pr ∼ 41.05 μC/cm²and Ec ∼ 8.1 kV/cm) were obtained for the sample sintered at 1150°C. © 2013 Copyright Taylor and Francis Group, LLC.